scholarly journals Experimental Fatigue Life Rule in Low Cycle Fatigue Region Based on Cyclic Strain Behavior of Specimen with Notches.

2002 ◽  
Vol 68 (670) ◽  
pp. 956-961 ◽  
Author(s):  
Katsuro SHINGAI
Keyword(s):  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Cyclic Strain ◽  
Cycle Fatigue ◽  
Strain Behavior

Cyclic Plastic Deformation of a Circular Plate With Work Hardening

1984 ◽  
Vol 106 (4) ◽  
pp. 336-341
Author(s):  
R. Winter
Keyword(s):  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Nonlinear Behavior ◽  
Strain Curve ◽  
Strain Range ◽  
Cyclic Strain ◽  
Cyclic Stress ◽  
Cycle Fatigue ◽  
Stress Strain ◽  
Element Analysis

An experimental and theoretical study was performed of the nonlinear behavior of a simply supported flat circular aluminum plate under reversed cyclic central load. The application is for the analysis of cyclic stress and strain of structural components in the plastic range for predicting low-cycle fatigue life. The main purpose was to determine the relative accuracy of an elastic-plastic large deformation finite element analysis when the material properties input data are derived from monotonic (noncyclic) stress-strain curves versus that derived from cyclic stress-strain curves. The results showed that large errors could be induced in the theoretical prediction of cyclic strain range when using the monotonic stress-strain curve, which could lead to large errors in predicting low-cycle fatigue life. The use of cyclic stress-strain curves, according to the model developed by Morrow, et al., proved to be accurate and convenient.

Cyclic stress–strain behavior and low cycle fatigue life of cast A356 alloys

2011 ◽  
Vol 33 (12) ◽  
pp. 1600-1607 ◽  
Author(s):  
M.S. Song ◽  
Y.Y. Kong ◽  
M.W. Ran ◽  
Y.C. She
Keyword(s):  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Cyclic Stress ◽  
Cycle Fatigue ◽  
Stress Strain ◽  
Strain Behavior

Effect of Static Pre-Strain on Low Cycle Fatigue Life of AISI 316L Stainless Steel

2011 ◽  
Vol 462-463 ◽  
pp. 65-69
Author(s):  
Tomohiro Ido ◽  
Jun Komotori
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
316L Stainless Steel ◽  
Early Stage ◽  
Low Cycle Fatigue ◽  
Cyclic Strain ◽  
Aisi 316L ◽  
Cycle Fatigue ◽  
Aisi 316L Stainless Steel ◽  
Work Softening

In order to clarify the effects of a great amount of static pre-strain (1/4 cycle) on fatigue life of AISI 316L stainless steel, strain controlled low cycle fatigue tests were carried out. Hardness and fracture ductility of specimens were measured. Results showed that in the case of a specimen with p=0.01, static pre-strain of 0.16 noticeably reduced a fatigue life. To clarify the reasons for the decrease in fatigue life with pre-strain, the maximum stress amplitude of the hysteresis loop was measured. In the case of the specimen with p=0.01, work softening was observed in the early stage of fatigue life. On the other hand, when the cyclic plastic strain ranges were p=0.10, no softening was observed. These results suggest that work softening is significant in determining the fatigue life of the specimens at a relatively low level of applied cyclic strain.

Low-Cycle Fatigue Performance of Buckling Restrained Braces and Assessment of Cumulative Damage under Severe Earthquakes

2018 ◽  
Vol 763 ◽  
pp. 867-874
Author(s):  
Yu Shu Liu ◽  
Ke Peng Chen ◽  
Guo Qiang Li ◽  
Fei Fei Sun
Keyword(s):  
Fatigue Life ◽  
Energy Dissipation ◽  
Structural Reliability ◽  
Low Cycle Fatigue ◽  
Engineering Application ◽  
Fatigue Performance ◽  
Cycle Fatigue ◽  
Variable Amplitude ◽  
Buckling Restrained Braces ◽  
Energy Dissipation Devices

Buckling Restrained Braces (BRBs) are effective energy dissipation devices. The key advantages of BRB are its comparable tensile and compressive behavior and stable energy dissipation capacity. In this paper, low-cycle fatigue performance of domestic BRBs is obtained based on collected experimental data under constant and variable amplitude loadings. The results show that the relationship between fatigue life and strain amplitude satisfies the Mason-Coffin equation. By adopting theory of structural reliability, this paper presents several allowable fatigue life curves with different confidential levels. Besides, Palmgren-Miner method was used for calculating BRB cumulative damages. An allowable damage factor with 95% confidential level is put forward for assessing damage under variable amplitude fatigue. In addition, this paper presents an empirical criterion with rain flow algorithm, which may be used to predict the fracture of BRBs under severe earthquakes and provide theory and method for their engineering application. Finally, the conclusions of the paper were vilified through precise yet conservative prediction of the fatigue failure of BRB.

scholarly journals Fatigue Testing of Wearable Sensing Technologies: Issues and Opportunities

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4070
Author(s):  
Andrea Karen Persons ◽  
John E. Ball ◽  
Charles Freeman ◽  
David M. Macias ◽  
Chartrisa LaShan Simpson ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Prediction Models ◽  
Fatigue Testing ◽  
Low Cycle Fatigue ◽  
Wearable Sensors ◽  
Fatigue Tests ◽  
Proof Of Concept ◽  
Cycle Fatigue ◽  
Wearable Sensing ◽  
Failure Data

Standards for the fatigue testing of wearable sensing technologies are lacking. The majority of published fatigue tests for wearable sensors are performed on proof-of-concept stretch sensors fabricated from a variety of materials. Due to their flexibility and stretchability, polymers are often used in the fabrication of wearable sensors. Other materials, including textiles, carbon nanotubes, graphene, and conductive metals or inks, may be used in conjunction with polymers to fabricate wearable sensors. Depending on the combination of the materials used, the fatigue behaviors of wearable sensors can vary. Additionally, fatigue testing methodologies for the sensors also vary, with most tests focusing only on the low-cycle fatigue (LCF) regime, and few sensors are cycled until failure or runout are achieved. Fatigue life predictions of wearable sensors are also lacking. These issues make direct comparisons of wearable sensors difficult. To facilitate direct comparisons of wearable sensors and to move proof-of-concept sensors from “bench to bedside,” fatigue testing standards should be established. Further, both high-cycle fatigue (HCF) and failure data are needed to determine the appropriateness in the use, modification, development, and validation of fatigue life prediction models and to further the understanding of how cracks initiate and propagate in wearable sensing technologies.

Uniaxial Ratcheting and Low-Cycle Fatigue Failure of U75V Rail Steel

2016 ◽  
Vol 853 ◽  
pp. 246-250 ◽  
Author(s):  
Tao Fang ◽  
Qian Hua Kan ◽  
Guo Zheng Kang ◽  
Wen Yi Yan
Keyword(s):  
Fatigue Life ◽  
Strain Amplitude ◽  
Stress Ratio ◽  
Stress Amplitude ◽  
Rail Steel ◽  
Low Cycle Fatigue ◽  
Mean Stress ◽  
Cycle Fatigue ◽  
Ratcheting Strain ◽  
Cyclic Straining

Experiments on U75V rail steel were carried out to investigate the cyclic feature, ratcheting behavior and low-cycle fatigue under both strain- and stress-controlled loadings at room temperature. It was found that U75V rail steel shows strain amplitude dependent cyclic softening feature, i.e., the responded stress amplitude under strain-controlled decreases with the increasing number of cycles and reaches a stable value after about 20th cycle. Ratcheting strain increases with an increasing stress amplitude and mean stress, except for stress ratio, and the ratcheting strain in failure also increases with an increasing stress amplitude, mean stress and stress ratio. The low-cycle fatigue lives under cyclic straining decrease linearly with an increasing strain amplitude, the fatigue lives under cyclic stressing decrease with an increasing mean stress except for zero mean stress, and decrease with an increasing stress amplitude. Ratcheting behavior with a high mean stress reduces fatigue life of rail steel by comparing fatigue lives under stress cycling with those under strain cycling. Research findings are helpful to evaluate fatigue life of U75V rail steel in the railways with passenger and freight traffic.

A Multi-Level Low Cycle Fatigue Damage Model for Forging Die Material

2006 ◽  
Vol 514-516 ◽  
pp. 804-809
Author(s):  
S. Gao ◽  
Ewald Werner
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Low Cycle Fatigue ◽  
Damage Model ◽  
Fatigue Loading ◽  
Cycle Fatigue ◽  
Die Material ◽  
Multi Level ◽  
Loading Sequence ◽  
Forging Die

The forging die material, a high strength steel designated W513 is considered in this paper. A fatigue damage model, based on thermodynamics and continuum damage mechanics, is constructed in which both the previous damage and the loading sequence are considered. The unknown material parameters in the model are identified from low cycle fatigue tests. Damage evolution under multi-level fatigue loading is investigated. The results show that the fatigue life is closely related to the loading sequence. The fatigue life of the materials with low fatigue loading first followed by high fatigue loading is longer than that for the reversed loading sequence.

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